Hydrogen reduction of mixed oxides for CO2-free synthesis of ferro-alloys
To address the climate change challenge, it is evident that the world must shift towards green energy. Globally, the steel industry contributes about 11% of total CO2 emissions. Decarbonizing the iron and steel industry has significant benefits for reducing the impact of climate change and creating a sustainable future. Hydrogen metallurgy is the technology that uses hydrogen as a reducing agent instead of carbon and produces water as a by-product. When the utilized hydrogen is produced from a clean energy source like the electrolysis of water with renewable source of electricity, it leads to metals with a near-zero carbon footprint. Hydrogen reduction of iron oxide is technologically and commercially deployed. However, ferroalloys - such as Fe-Cr, Fe-Ni, Fe-Mn, Fe-Mo and Fe-W - are usually added to molten iron in electric arc furnaces to create alloyed steels. Relative to iron, these alloying elements have a higher carbon footprint per unit mass, thus necessitating the decrease of their carbon footprint to achieve green steel production. The conventional fabrication uses an electric arc furnace to reduce mixed oxides (such as Fe2O3 and NiO) at very high temperatures while requiring the use of pure elements (Al and Si) as reductants, each with a high carbon footprint to produce. This research aims to demonstrate and investigate the co-reduction of mixed oxides with hydrogen to produce the ferro-alloys at near-zero carbon footprint. We are proceeding with a fundamental material-science investigation of mechanisms of H2-reduction of blends of iron oxide and other element oxides, and their effects on the resultant steel or ferroalloy microstructure and mechanical properties.